This invention relates to motor vehicles having collision energy conversion arrangements.
Conventionally, the structure of the end portion of a motor vehicle in which the motor vehicle engine is located includes the free ends of two laterally-spaced longitudinal frame members of the chassis extending away from the passenger compartment, to which a transverse bumper is attached. When force is applied to the bumper in a collision, kinetic energy is converted into work of deformation of the longitudinal frame members, for example, a bellows-like deformation, and a consequent reduction in the length of the longitudinal members. This conventional collision energy-absorbing construction presents difficulties, however, if there is a so-called pillar impact, especially in the neighborhood of the central longitudinal plane of the vehicle, i.e., a locally-concentrated impact on the bumper between its supports at the ends of the longitudinal members because, in that case, the bumper, and a radiator that may be positioned behind it, will be greatly deformed. This is especially dangerous because there will then be the danger of displacement of the engine toward the passenger compartment, invading particularly the leg room of the occupants.
German Offenlegungsschrift No. 22 13 725 discloses a motor vehicle that includes an energy-absorbing arrangement between a part of the powertrain connected to the engine and the passenger compartment. This energy-absorbing arrangement is positioned essentially below the passenger compartment and is accommodated by appropriate conformation of the floorplate of the vehicle. Assuming that a bumper suspension also requires energy-absorbing devices not disclosed in that document, this known vehicle requires a considerable additional cost to provide for the absorption of collision-impact kinetic energy of the vehicle engine.